1. Field of the Invention
The present invention relates to luminaires and more particularly to luminaire reflectors to be used with high intensity light sources.
2. Description of the Prior Art
The present invention relates to bowl-type reflectors for use with high intensity light sources. A typical bowl-type luminaire of the prior art is illustrated in U.S. Pat. No. 3,950,638 which issued on Apr. 13, 1976 for High Intensity Indirect Lighting Fixture. Such luminaire reflectors are utilized with high intensity discharge lamps such as high pressure sodium lamps.
The object of such reflectors is to attempt to optically control light reflections and distribution to increase efficiency to a maximum and to prevent introduction of significant glare.
Such luminaires are generally utilized in schools, offices, shops, etc., for indirect lighting. In order to provide acceptable uniformity of lumination across the ceiling, it is desirable to achieve a light distribution from the luminaire which is generally referred to in the industry as a bat-wing distribution. It is a further object in the industry to achieve such a distribution with a luminaire which has very high efficiency.
However, a significant problem with luminaire reflectors of the prior art is that in order to obtain the highest efficiency, it is necessary to use a clear lamp as opposed to a phosphor lamp, and when such high intensity clear discharge lamps are utilized in reflectors of the prior art, the reflectors do not produce a smooth or uniform light distribution. It is further obvious that it is desirable in the interest of obtaining high efficiencies to use highly polished reflectors. Here again, with the luminaires of the prior art, undesirable light distribution is produced when the combination of a clear lamp and highly polished reflectors are utilized. The reflectors of the prior art produce ununiform illumination or light distribution with hot spots, strips and striations. Thus, in order to hide these deficiencies, many of the manufacturers of prior art luminaires use unpolished reflectors and phosphor-coated discharge lamps. The result, of course, is that the overall efficiency of the luminaire is greatly reduced.
It is a principal object of the present invention to provide a luminaire for high intensity discharge lamps which is void of the aforementioned disadvantages, and may be utilized with a clear lamp and highly polished reflector surfaces and still achieve uniform illumination and light distribution without offensive reflected light patterns with an overall efficiency of over 77%.